@article{LoodTikkKruegeretal.2022,
  author    = {Lood, Kajsa and Tikk, Triin and Kr{\"u}ger, Mandy and Schmidt, Bernd},
  title     = {Methylene capping facilitates cross-metathesis reactions of enals},
  series = {The journal of organic chemistry},
  volume    = {87},
  journal   = {The journal of organic chemistry},
  number    = {5},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0022-3263},
  doi       = {10.1021/acs.joc.1c02851},
  pages     = {3079 -- 3088},
  year      = {2022},
  abstract  = {Four combinations of type-I olefins isoeugenol and 4-hydroxy-3-methoxystyrene with type-II olefins acrolein and crotonaldehyde were investigated in cross-metathesis (CM) reactions. While both type-I olefins are suitable CM partners for this transformation, we observed synthetically useful conversions only with type-II olefin crotonaldehyde. For economic reasons, isoeugenol, a cheap xylochemical available from renewable lignocellulose or from clove oil, is the preferred type-I CM partner. Nearly quantitative conversions to coniferyl aldehyde by the CM reaction of isoeugenol and crotonaldehyde can be obtained at ambient temperature without a solvent or at high substrate concentrations of 2 mol.L-1 with the second-generation Hoveyda-Grubbs catalyst. Under these conditions, the ratio of reactants can be reduced to 1:1.5 and catalyst loadings as low as 0.25 mol \% are possible. The high reactivity of the isoeugenol/crotonaldehyde combination in olefin metathesis reactions was demonstrated by a short synthesis of the natural product 7-methoxywutaifuranal, which was obtained from isoeugenol in a 44\% yield over five steps. We suggest that the superior performance of crotonaldehyde in the CM reactions investigated can be rationalized by "methylene capping", i.e., the steric stabilization of the propagating Ru-alkylidene species.},
  language  = {en}
}
@article{LoodSchmidt2020,
  author    = {Lood, Kajsa and Schmidt, Bernd},
  title     = {Stereoselective synthesis of conjugated polyenes based on tethered olefin metathesis and carbonyl olefination},
  series = {The journal of organic chemistry},
  volume    = {85},
  journal   = {The journal of organic chemistry},
  number    = {7},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0022-3263},
  doi       = {10.1021/acs.joc.0c00446},
  pages     = {5122 -- 5130},
  year      = {2020},
  abstract  = {The combination of a highly stereoselective tethered olefin metathesis reaction and a Julia-Kocienski olefination is presented as a strategy for the synthesis of conjugated polyenes with at least one Z-configured C=C bond. The strategy is exemplified by the synthesis of the marine natural product (+)-bretonin B.},
  language  = {en}
}
@phdthesis{Lood2021,
  author    = {Lood, Kajsa},
  title     = {Stereoselective Construction of C-C Double Bonds via Olefin Metathesis: From Tethered Reactions to Water-Soluble Catalysts for Stereoretentive Metathesis},
  doi       = {10.25932/publishup-53914},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-539142},
  school      = {Universit{\"a}t Potsdam},
  pages     = {95},
  year      = {2021},
  abstract  = {Natural products have proved to be a major resource in the discovery and development of many pharmaceuticals that are in use today. There is a wide variety of biologically active natural products that contain conjugated polyenes or benzofuran structures. Therefore, new synthetic methods for the construction of such building blocks are of great interest to synthetic chemists. The recently developed one-pot tethered ring-closing metathesis approach allows for the formation of Z,E-dienoates in high stereoselectivity. The extension of this method with a Julia-Kocienski olefination protocol would allow for the formation of conjugated trienes in a stereoselective manner. This strategy was applied in the total synthesis of conjugated triene containing (+)-bretonin B. Additionally, investigations of cross metathesis using methyl substituted olefins were pursued. This methodology was applied, as a one-pot cross metathesis/ring-closing metathesis sequence, in the total synthesis of benzofuran containing 7-methoxywutaifuranal. Finally, the design and synthesis of a catalyst for stereoretentive metathesis in aqueous media was investigated.},
  language  = {en}
}